Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/04—Dispersions; Emulsions
  • A61K8/06—Emulsions
  • A61K8/062—Oil-in-water emulsions
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
  • A61K8/81—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • A61K8/8141—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
  • A61K8/8152—Homopolymers or copolymers of esters, e.g. (meth)acrylic acid esters; Compositions of derivatives of such polymers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q19/00—Preparations for care of the skin
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K2800/00—Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
  • A61K2800/20—Chemical, physico-chemical or functional or structural properties of the composition as a whole
  • A61K2800/30—Characterized by the absence of a particular group of ingredients
  • A61K2800/33—Free of surfactant

Definitions

• the invention relates to a stable oil-in-water (O / W) emulsion comprising oil globules having an average size of less than 20 microns and containing at least 15% of oily phase and at least one copolymer of fatty chain carboxylic acid.
• the invention also relates to the process for preparing such an emulsion and to its use in the cosmetic and / or dermatological fields.
• the cosmetic compositions are most often in the form of an emulsion of the oil-in-water type, comprising an oily phase dispersed homogeneously in an aqueous phase.
• the size of the globules constituting the fatty phase is generally greater than several tens of microns.
• Such emulsions may have insufficient cosmetic (oily feel) and physical (stability) properties.
• Insufficient stability results in the appearance of a phenomenon of separation (phase shift) between the aqueous and oily phases of the emuision. This instability harms the conservation of emulsions.
• emulsifying agents or surfactants
• surfactants which are put at the interface of the aqueous and oily phases.
• the presence of surfactants has several drawbacks, in particular it most often requires making the hot sauce, which in particular limits the nature of the active agents to be introduced into the sauce. In particular, this process excludes the use of heat-sensitive active ingredients. Also, are we trying to get rid of surfactants. In addition, surfactants can cause irritation, especially in people with sensitive skin.
• the Applicant has unexpectedly discovered that it is possible to prepare emulsions having a high level of oily phase and free of surfactant, by having oil globules having an average size of less than 20 microns and by using a copolymer constituted of a majority fraction of C 3 -C 6 monoolefinically unsaturated carboxylic acid monomer or of its anhydride and of a minority fraction of fatty chain ester monomer of acrylic acid.
• the present invention therefore relates to an emulsion comprising an oily phase dispersed in an aqueous phase, characterized in that the globules of the oily phase have an average size of less than 20 microns, in that the oily phase constitutes at least 15% in weight relative to the total weight of the emuision and in that the aqueous phase contains at least one copolymer consisting of a majority fraction of monoolefinically unsaturated C 3 -C 6 carboxylic acid monomer or of its anhydride and of a minority fraction of fatty chain ester monomer of acrylic acid, and in that it is free of surfactant.
• copolymers used in the emulsion of the invention have the advantage, compared to the surfactants usually used, not only of stabilizing the emulsion but also of gelling it. In addition, unlike surfactants, they do not penetrate the skin, which greatly reduces the risk of irritation.
• the copolymers used in the emulsions according to the present invention are prepared by polymerizing a preponderant amount of monoolefinically unsaturated carboxylic acid monomer or its anhydride to a smaller amount of fatty chain acrylic ester monomer.
• the term fatty chain is understood to mean a linear or branched alkyl radical containing from 8 to 30 carbon atoms.
• the amount of carboxylic acid monomer or its anhydride is preferably from 80 to 98% by weight and more particularly 90 to 98% by weight while 'that the acrylic ester is present in amounts ranging from 2 to 20% by weight and more particularly from 1 to 10% by weight, the percentages being calculated relative to the total weight of the two monomers.
• the preferred carboxylic monomers are chosen from those corresponding to the following formula (I):
• the particularly preferred carboxylic monomers are chosen from acrylic acid, methacrylic acid or their mixtures.
• the fatty chain acrylic ester monomers are preferably chosen from those corresponding to formula (II) below:
• R is chosen from the group formed by hydrogen, the methyl radical and the ethyl radical, and R 2 is a C 8 -C 30 alkyl group.
• ester monomers are those for which R. 1 is hydrogen or a methyl radical and R 2 is a C 10 -C 22 alkyl group.
• the copolymer used in the emulsion of the invention can optionally be crosslinked using a crosslinking agent used in an amount ranging from 0.1 to 4%, preferably from 0.2 to 1% by weight relative to the total weight of carboxylic monomers and acrylic ester monomers.
• copolymers are described in document EP-A-0268164 and are obtained according to the preparation methods described in this same document.
• the copolymer is used in the emulsion according to the invention in concentrations preferably ranging from 0.1 to 4% by weight and more particularly from 0.1 to 2% by weight relative to the total weight of the emulsion.
• the emulsion of the invention is free of surfactant.
• this emulsion has the advantage of allowing the incorporation of heat-sensitive active agents and of not being irritating for particularly sensitive skin.
• the average size of the oily phase globules is less than 20 microns, and it preferably ranges from 0.5 to 15 microns. Due to the fineness of these oil globules, the emulsion obtained has particularly satisfactory sensory and visual qualities.
• the nature of the oily phase of the emulsion according to the invention is not critical.
• the oily phase can thus consist of all fatty substances and in particular oils, conventionally used in the cosmetic and dermatological fields.
• the other fatty substances likely to be present in the oily phase can be for example fatty acids, fatty alcohols and waxes (liquid jojoba wax).
• the oily phase of the emuision may represent from 15 to 45% by weight and better still from 20 to 30% by weight of the total weight of the emuision.
• the emulsion according to the invention can be used in all areas where this type of dosage form is advantageous, and in particular in the cosmetic and dermatological fields.
• it when it constitutes a cosmetic and / or dermatological composition, it also advantageously contains a physiologically acceptable medium, that is to say compatible with the skin, mucous membranes, nails and / or hair.
• the emulsions which are the subject of the invention find their application in a large number of cosmetic and / or dermatological treatments of the skin, mucous membranes and hair, including the scalp, in particular for the protection, care, cleaning and / or make-up of the skin and / or mucous membranes, for the protection, care and / or hair cleaning and / or for the therapeutic treatment of the skin, hair and / or mucous membranes (lips).
• the emulsions according to the invention can for example be used as care and / or cleaning products for the face in the form of creams or milks or as makeup products (skin and lips) by incorporation of fillers, pigments or dyes .
• the subject of the invention is also the cosmetic use of the emulsion as defined above for the treatment, protection, care and / or cleaning of the skin, mucous membranes and / or the hair, and / or for making up the skin and / or mucous membranes.
• the subject of the invention is also the use of the emulsion as defined above for the manufacture of a dermatological composition intended for the treatment and / or the protection of the skin, mucous membranes and / or the hair.
• the emulsions of the invention may contain adjuvants customary in the cosmetic or dermatological field, such as hydrophilic or lipophilic active agents, preservatives, antioxidants, perfumes, solvents, fillers, filters , coloring matters, basic agents (triethanolamine) or acids and also lipid vesicles.
• adjuvants customary in the cosmetic or dermatological field, such as hydrophilic or lipophilic active agents, preservatives, antioxidants, perfumes, solvents, fillers, filters , coloring matters, basic agents (triethanolamine) or acids and also lipid vesicles.
• These adjuvants are used in the usual proportions in the cosmetic or dermatological field, and for example from 0.01 to 30% of the total weight of the emulsion, and they are, depending on their nature, introduced into the aqueous phase or into the phase oily emulsion, or in vesicles.
• These adjuvants and their concentrations must be such that they do not modify the property sought for the emulsion
• gelling agents such as clays, polysaccharide gums (xanthan gum), carboxyvinyl polymers or carbomers. These gelling agents are used at concentrations ranging from 0.1 to 10%, preferably 0.1 to 5% and better still from 0.1 to 3% of the total weight of the composition.
• the emulsions of the invention can optionally be free of solvent. This also goes in the direction of a slightly aggressive and non-irritating emulsion capable of being used by people with sensitive skin. However, if necessary, they can contain a solvent, in particular a lower alcohol containing from one to six carbon atoms, more particularly ethanol. The amount of solvent can range up to 30% of the total weight of the composition.
• the emulsions according to the invention can be prepared by any suitable means making it possible to obtain sizes of oily globules of less than 20 microns. According to a preferred embodiment of the invention, they are prepared using a microporous membrane, this technique making it possible to obtain a size of globules particularly suited to the aim of the invention and in particular of calibrated, monodispersed oil globules. Such a technique is described for example in document EP-A-546,174.
• the subject of the invention is also a process for manufacturing the emulsion as defined above, consisting in introducing under pressure the oily phase into the aqueous phase containing the copolymer, through a porous glass membrane hydrophilic having an average pore size ranging from 0.1 to 5 ⁇ m and preferably from 0.3 to 3 ⁇ m, at a pressure greater than the critical pressure.
• the membrane is previously treated under vacuum and ultrasound in demineralized water containing approximately 2 grams per liter of aqueous phase of the composition according to the invention, this treatment lasting approximately one hour.
• critical pressure is understood to mean the minimum pressure necessary for the introduction of a phase dispersed in a continuous phase through a porous glass membrane having a determined pore size.
• the critical pressure (in kPa) is defined by the following equation:
• the pressure used is preferably Pc + 20 kPa.
• a membrane having a pore size ranging from 0.1 to 5 ⁇ m can be used, for example, using a pressure preferably ranging from 350 to 30 kPa (3.5 to 0.3 bars).
• the membrane used has a pore size of 0.3 ⁇ m, 0.7 ⁇ m or 2.8 ⁇ m and a pressure ranging from 220 to 320 kPa (2.2 to 3.2 bar) is then used. ), from 140 to 200 kPa (1, 4 to 2 bars) and from 30 to 70 kPa (0.3 to 0.7 bars).
• Volatile silicone oil (cyclopentasiloxane) 20% Procedure: A membrane having a pore size of 0.7 ⁇ m is immersed in one liter of demineralized water containing 2 grams of phase A, then it is placed under vacuum and ultrasound for one o'clock.
• phase A is pumped to pass inside the membrane.
• Phase B is pressurized up to the critical pressure of 170 kPa (1.7 bar).
• Phase B is then emulsified in phase A under a pressure of 190 kPa (1.9 bars).

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9531339

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (1)

Citations (1)

Family Cites Families (1)

• 1998
  • 1998-10-08 FR FR9812622A patent/FR2784310B1/fr not_active Expired - Fee Related
• 1999
  • 1999-10-04 EP EP99946286A patent/EP1047372A1/fr not_active Withdrawn
  • 1999-10-04 JP JP2000575467A patent/JP2002527531A/ja active Pending
  • 1999-10-04 KR KR10-2000-7006168A patent/KR100388692B1/ko not_active IP Right Cessation
  • 1999-10-04 CA CA002312032A patent/CA2312032A1/fr not_active Abandoned
  • 1999-10-04 BR BR9915585-0A patent/BR9915585A/pt not_active IP Right Cessation
  • 1999-10-04 WO PCT/FR1999/002361 patent/WO2000021491A1/fr not_active Application Discontinuation

Patent Citations (1)

Also Published As

Similar Documents

Legal Events